Spiders and Their Near Relatives 



Padua, in parts, which appeared in the years 1885 to 1899. An 

 older standard work is that of Megnin, Les Parasites et les Maladies 

 Parasitaires, Paris, 1880. 



Twenty-two of the families of mites are known to be rep- 

 resented in our fauna.* These twenty-two families are grouped 

 into eight superfamilies. We have space here for only a brief 

 discussion of the superfamilies. The eight superfamilies are 

 separated by Banks as follows: 



A. Abdomen annulate, prolonged behind; very minute forms; 

 many with but four legs. P. 93. Demodicoidea 



AA. Abdomen not annulate nor prolonged behind; all with 

 eight legs in the adult state. 

 B. With a distinct spiracle upon a stigmal plate on each side 

 of the body, usually below, above the third or fourth 

 coxae or a little behind; palpi free; skin often cori- 

 aceous or leathery; tarsi often with a sucker. 

 C. Hypostome large, furnished below with many recurved 

 teeth; venter with furrows; skin leathery; large 

 forms, usually parasitic. P. 89. Ixodoidea 



CC. Hypostome small, without teeth; venter without fur- 

 rows; body often with coriaceous shields, posterior 

 margin never crenulate; no eyes. P. 90 



Gamasoidea 



BB. No such distinct spiracle in a stigmal plate on this part 



of the body. 



C. Body usually coriaceous, with few hairs ; with a specialized 



seta arising from a pore near each posterior corner of 



the cephalothorax; no eyes; mouth-parts and palpi 



very small; ventral openings of the abdomen large; 



never parasitic; tarsi never with a sucker. P. 91. 



Oribatoidea 

 CC. Body softer, without such specialized seta. 



D. Living in water. P. 88. Hydrachnoidea 



DD. Not living in water. 



E. Palpi small, three-jointed, adhering for some 

 distance to the lip; ventral suckers at genital 

 opening or near anal opening usually present; 

 no eyes; tarsi often end in suckers; beneath the 



* In Banks' Treatise twenty-five families are described; but in his later catalogue three of these 

 families are united with other families. 



86 



